1. Field of the Invention
The present invention relates to a power nailer, and more particularly, to a nailing depth adjusting and positioning device for a power nailer.
2. Description of the Related Art
A conventional nailing depth adjusting devices for power nailers are shown in FIGS. 1 and 2, disclose two power nailers with same technological principle, which are both comprised of a distal end threaded link 10 to cooperate with a plate 11, an interior threaded nut 12 and a spring 13. When an user operates an conventional power nailer, the plate 11 contacts a work piece""s surface, and then the link 10 is actuated by pushing the plate 11 against the work piece, such that the power nailer is in a stand-by condition, as long as the user pushes a trigger, a nail can be rapidly ejected. The starting distance of the plate 11 only can be adjusted by cooperating with a work piece, accordingly, in operation, the plate 11 is usually movable by rotating the nut 12 whereby to adjust the distance between power nailer and work piece. Although such conventional device still can be used and capable of adjusting the depth of nailing, during real operation, there are still drawbacks to be improved and some problems will occur:
1. Starting distance of the plate 11 is adjusted by rotating the nut 12 whereby to move the plate 11, but the distal thread of the link 10 will not be engaged well with the interior thread of the nut 12 when the link 10 is over moved by rotating the nut 12 (when rotating the nut 12 too much), such that the link 10 disengages from the nut 12, endangering the safe operation.
2. Starting distance of the plate 11 has to keep equivalence by cooperating with different work pieces, in this case, the successive maintenance of the distance becomes very important. While there is no preferred positioning design in conventional nailing depth adjusting for a power nailer to fix the distance of the plate 11, it is inconvenient for users to adjust the nut 12 repeatedly during operation.
The present invention has arisen to mitigate the afore-described disadvantages of the conventional nailing depth adjusting and positioning device for a power nailer.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional web-shaped product.
The primary objective of the present invention is to provide a nailing depth adjusting and positioning device for a power nailer having a circular groove formed in a rotatable member and a retainer ring located in a link whereby to prevent the rotatable member from being overly rotated (to protect the distal thread), and the disengagement of the device.
Another objective of the present invention is to provide a nailing depth adjusting and positioning device for a power nailer having a steel ball and a spring mounted in the rotatable member, the steel ball cooperates with the several gaps in the safety device to locate the rotatable member, such that the starting distance of the device may stably be adjusted and the user has not to adjust repeatedly.
In accordance with the present invention, there is provided a nail depth adjusting and positioning device for a power nailer comprising a link which is a rod moveably mounted on the power nailer. The link has a nose rod on a first end thereof to connect to a trigger of said power nailer, and a connection plate extending laterally from a second end of said link. The connection plate has a sleeve and a top plate defined in a distal end thereof. A step hole is formed in the sleeve, and a circular groove is defined adjacent to an opening of the sleeve which faces toward a muzzle of the power nailer. The step hole has a bigger bore at its upper position and a smaller threaded bore at its lower position. The circular groove is defined two through holes in connection with the step hole. A spring has a first end mounted to the sleeve and a second end engaging a body of the power nailer. A rotatable member includes a wheel body, a step rod and a positioning rod. The wheel body has a plurality of anti-sliding threads on a surface thereof. The step rod is formed at a side of the wheel body and received in the step hole of the sleeve. The step rod includes a screw section, a sliding section and a ring section. The screw section has a plurality of threads on a surface thereof, and is located at a first end of the step rod. The screw section is threadly engaged with a smaller threaded bore of the step hole. The sliding section is located at a second end of the step rod adjacent to the wheel body, and the ring section is located between the screw section and the sliding section. A side of said ring section forms a stopper due to the diameter of said ring section is bigger than the diameter of the sliding section. The length of the sliding section is shorter than the length of the screw section. In addition, the positioning rod has a circular groove defined threreon, and a recess hole is defined between said circular groove and the wheel body. A spring and steel ball are put into the recess hole in turn. A push member has a crown bar in correspondence with a work piece and a positioning seat extends laterally from an end of the crown bar. The positioning seat has a central hole defined therethrough and a plurality of gaps defined in an inner periphery defining the central hole. The push member is mounted to the positioning rod and the steel ball mates with one of the gaps so that when the rotatable member is rotated, the steel ball can change the position from one gap to the other. A C-shaped fastener is located in the circular groove so that the rotatable member will not disengage from the central hole of the push member because a diameter of the C-shaped fastener is larger than the central hole.